Flexible support brace

ABSTRACT

A flexible joint brace. The brace has a generally annular structure with a main section and at least one support section aligned along a plane of motion for the human limb or aligned along a meridian proximate to the joint. The main section is formed with larger holes throughout and the support section is formed with smaller holes, the smaller holes providing an increased volume of material that supports and stabilizes the underlying joint in the direction of movement affected by the injury or arthritis.

TECHNICAL FIELD

This disclosure relates generally to a flexible support brace fortherapeutic support and resistance to movement in joints, such as theknee, ankle, wrist and elbow.

BACKGROUND

Joint injuries are common for both competitive and recreationalathletes, or for those suffering from arthritis. For example, a sprainis a stretching or tearing of a ligament that joins one bone to another,and may be caused by a fall, twist or blow to the joint, while a strainis a twist, pull or tear of a muscle or tendon (tendons connect muscleto bone) caused by stretching or contracting the muscle or tendon morethan normal. Other types of injuries, such as bursitis, tendonitis, orrepetitive injuries (carpal tunnel syndrome), may be mild or severe.

While the knee is probably the most commonly injured joint, the ankle,wrist and elbow are also frequently injured. Taking steps to preventinjury is important, but once a joint injury has occurred, keeping thejoint stable is the primary goal for rehabilitation. To that end, thereare a number of commercial products that seek to provide support. Forexample, the Ace® bandage is a well-known elastic wrap that is used towrap around an injured joint, providing some degree of uniform supportthroughout the injured area. However, such a bandage does not providefocused support and/or resistance to movement based on the nature of theinjury or the particular joint movement.

There are also elastic braces sold by Ace and others specificallydesigned for the ankle, knee, elbow or wrist, for example. However,these location-specific braces are uniform in material construction, andstill do not provide adequate focused support and/or resistance to jointmovement based on the nature of the injury or the particular jointmovement.

Thus, it would thus be desirable to have an improved brace that isfocused on providing support and/or resistance to specific jointmovements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a human anatomical subject illustratingthe three primary planes of joint movement.

FIG. 2A is a front perspective view of a generic brace structure.

FIG. 2B is a top plan view of an alternative brace structure having oneside formed in a trapezoidal shape.

FIG. 3A is a front perspective view of a knee brace.

FIG. 3B is a front plan view illustrating a knee joint in four differentrotational positions.

FIG. 3C is a front perspective view of the knee brace of FIG. 3A showingthe axis of knee joint rotation.

FIG. 3D is a front plan view of a human right leg showing the myofascialmeridians running through the leg.

FIG. 3E is a front plan view illustrating the knee brace of FIG. 3A overthe knee joint of FIG. 3B in one of the bent positions.

FIG. 4 is a front perspective view of an ankle brace.

FIG. 5 is a front perspective view of a wrist brace.

FIG. 6 is a rear perspective view of an elbow brace.

DETAILED DESCRIPTION

1. Overview

This disclosure describes a flexible brace for stabilizing andsupporting an underlying joint. The brace is formed from a flexibleelastic material such as a silicone or polyurethane. The brace has agenerally annular structure with a main section formed with a pattern oflarge holes disposed throughout the main section, and at least onesupport section formed with a pattern of small holes aligned along aplane of motion of the underlying joint or a meridian proximate to thejoint. The smaller holes provide an increased volume of material thatsupports and stabilizes the underlying joint.

2. Joints and Myofascial Meridians

The human body may be considered an ordered collection of many bones,some connected by joints that permit bodily movement, such as knee,ankle, elbow and wrist, which are the initial focus of embodiments ofthe braces described herein. Of course, there are connective tissuessuch as ligaments, synovial fluid, etc., that facilitate jointoperation. The concept of myofascial meridians is used to describe linesconnective tissue that run throughout the body, linking all parts of thebody, and providing the organized structural forces required for motion.(See, e.g., Myers, T., “Anatomy Trains,” Journal Of Bodywork andMovement Therapies, vol. 1, issue 2, pp. 91-101, January 1997). All ofthe foregoing can be taken into account, as further discussed below, inconstructing a suitable brace to provide support for different physicalissues of the user.

It is helpful to provide a frame of reference for physical descriptions,and thus FIG. 1 illustrates an anatomical FIG. 10 having a knee 12,ankle 14, wrist 16 and elbow 18. The three primary planes of movementcan be described as: the sagittal plane 20, a vertical plane thatdivides the body into left half and right half; the frontal plane 22, avertical plane perpendicular to the sagittal plane that divides the bodyinto an anterior or ventral (front) half and a posterior or dorsal(rear) half; and the transverse plane 24, a horizontal plane thatdivides the body into upper and lower portions.

The most common joint movement is flexion and extension in the sagittalplane, typified by the hinge joint of the elbow, the modified hingejoint of the knee, and the condyloid joint of the wrist. The movement ofthe ankle hinge joint is a little more complex, including dorsiflexion(movement is the frontal plane); plantar flexion (movement in thesagittal plane); and a slight circumduction (movement in the transverseplane). Generally, the extensor muscles that create/assist the extensionmovement are weak compared to those that create/assist the flexionmovement.

3. Building a Support Brace, Generally

FIG. 2A illustrates one embodiment of an annular structure 200 formed asa flexible brace. The brace 200 can be formed by injection molding, forexample, using a silicone material such as Mold Star® silicone rubber orother suitable elastic materials. Although brace 200 is shown ascylindrical in shape, other embodiments can be made to better fit theknee, ankle, leg, wrist, elbow, and arm, as discussed below. Forexample, as shown in FIG. 2B, another brace 250 could be formed withanterior half 251 formed to have a semi-circular profile and theposterior half 252 formed with a trapezoidal profile to provide a betterfit over the knee, elbow, etc. Further, any such braces could be madeand sold in standard sizes, such as small, medium or large, or custommade to order. The advent of 3D printing to quickly and inexpensivelyform custom molds may facilitate production of custom braces.

Referring back to FIG. 2A, the annular brace 200 has a top ring 202 anda bottom ring 204, both formed as solid ribbons of material around thetop and bottom of the structure, with one or more sections or sidepanels having different size holes, such as panels 210 and 220, formedbetween the top and bottom rings. The side panels may be uniform inmaterial thickness and density, but preferably, the material will varyin thickness and/or density as a means to define support portions of thebrace as discussed below. For example, the panels may be moldedgenerally to a thickness of 2.5 mm, but additional material could beadded to specific support portions. For example, panel 210 covers mostof the area between the rings 202, 204, and may be molded with astandard thickness of 2.5 mm, while smaller panel 220 may be molded withan increased thickness of up to 5 mm to enhance the ability of thesmaller panel 220 to both stabilize the underlying joint and to storeenergy for resistance to movement of the joint. Friction bumps 206 maybe formed on the inside portion of the top ring 202 to help grip thebody above the joint and keep the brace from slipping.

In this embodiment, side panel 210 has a pattern of large holes 212formed throughout the panel. For example, the large holes 212 may beformed to have a diameter of 12.7 mm (½ inch). Side panel 220 covers asmaller, specifically targeted area of the brace, e.g., a verticalsection between the rings 202, 204, and has a pattern of smaller holes222 formed throughout that section, for example, with a diameter of 6.35mm (¼ inch). By making the holes 222 smaller, the side panel 220 orsupport panel has more material disposed through that section than sidepanel 210 and can therefore provide more support through a range ofmotion of the underlying joint. Thus, the support panel 220 should beformed along a line or section of the brace that is coplanar with theplane of motion for the underling joint, on the anterior side of thejoint. A circular section 230 having large holes 232 may be formed inthe middle of the smaller hole section 220 as less restrictive area forthe knee cap (patella) or the elbow, for example. More than one supportpanel may be formed in a brace to provide support along multiple planesof motion. Further, as noted above, an increased thickness of materialmay be used in regions having supports panels. Alternatively, or inaddition, support panels may be formed along one or more meridians ofthe body.

Thus, in general, a flexible brace can be designed to control any therange of motion for any joint. The use of thinner and thicker portionsof material in the brace, combined with the use of larger and smallerholes, can be engineered for particular physical issues to provideappropriate joint stabilization as well as energy storage to resistundesirable joint movements.

Although commercial processes are likely to create and use standardinjection type molds, the emergence of 3D printing processes may allow avariety of molds to be easily and inexpensive built with amazingaccuracy, in the shape of anything from a straight cylinder to a bentelbow. Software to create 3D objects is readily available, such asAdobe® Photoshop CS6 Extended software with 3D modeling option. Further,3D printers are also readily available, such as the MakerBot Replicator2 3D printer, or the FlashForge 3D printer. Such customization willenable the production of braces to control/stabilize any range of motionfor any limbs/joints. Further, although 3D printing is still in itsinfancy, it is conceivable that it could be used to produce the actualbraces rather than just the molds.

Creating an effective brace involves two steps. First, two fixed pointsare selected on the limbs to which the brace will be secured, then,material is formed between the two points so as to create a smoothsurface against the skin. The volume of the material may be varied indifferent planes of movement. Any material in linear series will befixed at the two points on the limb and stretched over the instantaneousaxis of rotation for the joint, thus decelerating the effective momentarm that acts around the axis of rotation.

Because the two points are fixed, the flexible material will lengthenaway from the joint center as the joint moves through a range of motionthat changes the joint angle. At the joint rest or starting position, notension is stored in the brace. However, at the end position, elasticenergy will be stored in the brace.

The Poisson effect is an important mechanical characteristic thatrelates to the forces that are applied and created across across-section of material. Basically, when a body is subject to auniaxial stress in one planar direction, a strain is created in theother two perpendicular planes that increases the dimension the materialin those perpendicular planes. The converse is also true. For example, abody experiencing a tensile load which generates an increase in itsaxial dimensions also generates a decrease in its transverse dimensions.Thus, by having top and bottom rings secured at a fixed point relativeto the joint, the brace will self-tighten onto the limb thereby helpingto stabilize the underlying joint(s) and hold the brace in place on thesurface of the skin, in combination with the use of friction bumps onthe inside of the rings.

As the brace de-forms about the joint center, the moment arm of thejoint is pushed out to the surface of the skin, thereby increasing theload applied to the brace. The change in the joint angle is proportionalto the amount of tension stored in the brace, and as the joint flexes,more energy is stored in the brace. Further, due to the Poisson effect,the tension is passed laterally through the brace wall as well ascircumferentially around the brace.

In general, any material that exists anterior to the joint center willdecrease knee flexion, and any material located posterior to the jointcenter will decrease knee extension. Likewise, material locatedlaterally to the knee will decrease varus loading, while materiallocated medially to the knee will decrease valgus loading.

If the brace has a uniform consistency and thickness, the wall createdagainst the skin makes it difficult to differentiate the volume ofmaterial and to vary loads in specific directions. However, by usingholes in the material and varying the circumference of the holes,effective stabilization and support for the underlying can be created.Thus, the use of larger holes presents less elastic in series therebycreating less resistance. However, the use of smaller holes puts moreelastic in series thereby creating more resistance in a given directionof movement. The ability to create a linear resistance in a specifieddirection applies to all three planes of movement and is essential tocreating smooth and efficient movement patterns.

Increasing the volume of material in selected areas between the ringsenables coordinating pressure over joint centers as they move throughranges of motion. Advantageous, the volume of material can be increasedby forming “straps” of additional material on the surface of the bracein the direction the myofascial meridians. The straps are formed as partof the initial molding of the brace. As the joint goes through flexionand extension, tension is passed though the elastic matrix pulling onthe straps to secure them as well as lengthening them across theinstantaneous joint center, much like bending a beam.

The placing of more material in line with the myofascial meridians helpsto secure the brace in place as well as help support and control thedynamic nature of the joint center and direct force over or in a planeof motion.

4. Support Brace for Knee

FIG. 3A illustrates a brace 300 formed to better fit and support theknee. For example, the top ring 302 and corresponding top portion of thebrace may have a larger diameter to better fit above the knee, and aslight rearward tilt. The bottom ring 304 and corresponding bottomportion of the brace have a smaller diameter to better fit below theknee. The posterior portion 310 of the brace 300 has a pattern of largediameter holes 312, while the anterior portion 320 of the brace has apattern of smaller diameter holes 322. Further, several larger holes 324are formed in correspondence with the patella. Thus the smaller holes322 provide a linear series resistance on the anterior side to flexionand extension movements of the knee joint.

FIG. 3B illustrates the knee joint 330 with the femur 332 in fourdifferent positions. In position I (332 a), the leg is straight with theknee in full extension. In position IV (332 d), the leg is bent at theknee in full flexion. Position II (332 b) and position III (332 c) areintermediate positions. When building any brace, the center of rotationfor the underlying joint is a key location. In some joints, however,like the knee, the center of joint rotation is not fixed in one spot,but moves with a flexion or extension movement. This movement is alsoillustrated in FIG. 3B, where point 334 a is the instantaneous center ofrotation when the knee is in position I; point 334 b is theinstantaneous center of rotation when the knee is in position II; point334 c is the instantaneous center of rotation when the knee is inposition III; and point 334 d is the instantaneous center of rotationwhen the knee is in position IV.

FIG. 3C is similar to FIG. 3A, but includes an axis of rotation 340around the instantaneous center point 334 superimposed on the knee brace300. Further, the relationship of significant meridian lines to the kneejoint is also shown on FIG. 3C. For example, the superficial front line(SFL) 350 is behind the center of the brace on the anterior side; thelateral line (LL) 352 is behind the outside portion of the knee joint;and the deep front line (DFL) 354 is behind the inside portion of theknee joint. These meridians are also illustrated relative to the rightknee in FIG. 3D.

FIG. 3E shows the brace 300 covering the knee joint 330 in position IIhaving center of rotation 334 b, with top ring 302 snugly fit above theknee and bottom ring 304 snugly fit below the knee.

An evaluation of the performance of the knee brace was performed using aseated knee extension machine. A vertical stack of weights was loadedonto the machine, and the subject performed weighted leg extensionsaccording to the standard control and test battery used by the NationalStrength and Conditioning Association (NSCA). For example, the testsstarted with high weight and low repetitions then moved to low weightand high repetitions.

Four different attributes were tested, namely, anaerobic power,anaerobic endurance, aerobic strength, and aerobic endurance. The trialsincluded a 5 minute warm-up on an exercise bicycle with no brace; then acontrol battery with no brace; and finally a test battery with brace.The trials indicated that, while wearing the knee brace, an increase ofapproximately 35% in anaerobic power was observed; an increase ofapproximately 37% in anaerobic endurance was observed; an increase ofapproximately 38.5% in aerobic strength was observed; and an increase ofapproximately 25% in aerobic endurance was observed;

5. Support Brace for Ankle

FIG. 4 illustrates a brace 400 formed to better fit and support theankle, the brace is formed in a L-shape between the top ring 402 and thebottom ring 404 to match the shape of the foot, with a heel opening 401.The top ring 402 is sized to fit snugly above the ankle, and the bottomring 404 is sized to fit around the foot. The posterior portion 410 andthe anterior portion 420 of the brace 400 have patterns of largediameter holes 412, while the inside portion 430 and outside portions440 have patterns of smaller diameter holes 432. The smaller holes 432are vertically oriented to follow the spiral line lateral meridians 450on both the medial and lateral portions of the ankle, while the largerholes 412 are vertically oriented on the posterior side of the ankle andalso vertically oriented to follow the superficial front line meridian452 on the anterior side. The smaller holes 432 provide a linear seriesresistance on both the medial and lateral portions of the ankle torotational movements of the ankle joint.

6. Support Brace for Wrist

FIG. 5 illustrates a brace 500 formed to better fit and support thewrist. The brace 500 is formed like a glove, with five ringed fingeropenings 504 at one end and a top ring 502 sized to fit snugly above thewrist. Patterns of large diameter holes 512 are formed through the palmarea 514 and through the area 516 below the thumb. However, it may bedesirable to have an open area of no material is the palm area to enablegripping a racket or club, or an area of less material for an injurysuch as carpal tunnel, which does not require restrictive pressure fromthe palm side. Area 516 below the thumb is a compressed zone because thehand pronates around axis 540 that runs through the joint center 534,and supinates in the resting position. Patterns of smaller holes 514 areoriented to follow the deep front arm line meridian 550 that runs fromthe outside of the wrist across to the end of thumb, and also to followthe deep back arm line 552 that runs along the outside of the hand. Thesmaller holes 514 provide a linear series resistance on both the insideand outside of the wrist to rotational movements of the wrist joint.

7. Support Brace for Elbow

FIG. 6 illustrates a brace 600 formed to better fit and support theelbow. The brace 600 is formed much like the knee brace 300, with a topring 602 sized to fit snugly above the elbow and a bottom ring 604 sizedto fit snugly below the elbow. Patterns of large diameter holes 612 areformed vertically along the entire length of the anterior section 610and also in the posterior section 614 above the elbow. Patterns ofsmaller holes 632 are oriented to follow the superficial back arm linemeridian 650 that runs straight through the elbow, and also to followthe deep back arm line meridian 652 that runs from the outside of theelbow on the anterior side across to the inside of the elbow on theposterior side. The smaller holes 632 provide a linear series resistanceto rotational movements of the elbow joint.

8. Conclusion

While one or more implementations have been described by way of exampleand in terms of the specific embodiments, it is to be understood thatone or more implementations are not limited to the disclosedembodiments. To the contrary, it is intended to cover variousmodifications and similar arrangements as would be apparent to thoseskilled in the art. Therefore, the scope of the appended claims shouldbe accorded the broadest interpretation so as to encompass all suchmodifications and similar arrangements.

The invention claimed is:
 1. A knee brace, comprising: an annularstructure formed of flexible elastic material to conform to a humanknee, the annular structure having a posterior section and an anteriorsection, the anterior section configured to conform to an anteriorregion of the human knee and cover a knee joint and formed with anincreased volume of the flexible elastic material relative to theposterior section, the posterior section configured to conform to aposterior region of the human knee.
 2. The knee brace of claim 1, theanterior section further comprising a first lateral section formed at afirst edge of the anterior section and configured to conform to a firstlateral region extending around an outside anterior portion of the kneejoint.
 3. The knee brace of claim 2, wherein the posterior section isformed to have a first plurality of holes having a first size, theanterior section is formed to have a second plurality of holes having asecond size, and the first lateral section is formed to have a thirdplurality of holes having the second size, wherein the second size issmaller than the first size in order to provide the increased volume offlexible elastic material relative to the posterior section.
 4. The kneebrace of claim 1, wherein the posterior section is formed to have afirst plurality of holes having a first size, and the anterior sectionis formed to have a second plurality of holes having a second size,wherein the second size is smaller than the first size in order toprovide the increased volume of flexible elastic material relative tothe posterior section.
 5. The knee brace of claim 4, wherein the firstand second plurality of holes are circular, and the second size is asmaller diameter than the first size.
 6. The knee brace of claim 1, theannular structure further comprising: a top circular ring configured tobe secured above the knee; and a bottom circular ring configured to besecured below the knee; wherein the posterior section and the anteriorsection are secured in a vertical orientation between the top ring andthe bottom ring, the posterior section formed with a first plurality ofholes having a first size, and the anterior section formed with a secondplurality of holes having a second size, wherein the second size issmaller than the first size thereby providing the increased volume offlexible elastic material relative to the posterior section.
 7. The kneebrace of claim 6, the anterior section further comprising: a firstlateral section formed at a first edge of the anterior section to have athird plurality of holes having the second size, the first lateralsection secured in a vertical orientation between the top ring and thebottom ring and configured to conform to a first lateral regionextending around an outside anterior portion of the knee joint.
 8. Theknee brace of claim 7, the anterior section further comprising: a secondlateral section formed at a second edge opposite the first edge of theanterior section to have a fourth plurality of holes having the secondsize, the second lateral section secured in a vertical orientationbetween the top ring and the bottom ring and configured to conform to aseconds lateral region extending around an inside anterior portion ofthe knee joint.
 9. The knee brace of claim 1, the anterior sectionfurther comprising a second lateral section formed at a second edgeopposite the first edge of the anterior section and configured toconform to a second lateral region extending around an inside anteriorportion of the knee joint.
 10. A knee brace, comprising: an annularstructure formed of flexible elastic material to substantially conformto a human knee, the annular structure having a posterior section and ananterior section, the anterior section configured to conform to ananterior region of the human knee and cover a knee joint, the posteriorsection formed with a first plurality of holes having a first size, andthe anterior section formed with a second plurality of holes having asecond size, wherein the second size is smaller than the first sizethereby providing an increased volume of the flexible elastic materialin the anterior section relative to the posterior section.
 11. The braceof claim 10, the anterior section further comprising: a first lateralsection formed at a first edge of the anterior section to have a thirdplurality of holes having the second size, the first lateral sectionconfigured to conform to a first lateral region extending around anoutside anterior portion of the knee joint.
 12. The knee brace of claim10, the anterior section further comprising a second lateral sectionformed at a second edge opposite the first edge of the anterior sectionand configured to conform to a second lateral region extending around aninside anterior portion of the knee joint.
 13. A knee brace, comprising:a first ring configured to be secured above a knee joint of a humanknee; a second ring configured to be secured below the knee joint; aposterior panel secured between the first ring and the second ring, theposterior panel is formed to have a first volume of flexible elasticmaterial and is configured to conform to a posterior region of the humanknee; and an anterior panel secured between the first ring and thesecond ring, the anterior panel is formed to have a second volume offlexible elastic material, the second volume is greater than the firstvolume, and is configured to conform to a posterior region of the humanknee.